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Brigantedinium asymmetricum
From Fensome et al., 2019:
Brigantedinium asymmetricum Matsuoka, 1987, p.56, pl.5, figs.10–12; text-fig.4B ex Head, 1996b, p.1231. Holotype: Matsuoka,
1987, pl.5, figs.10–11. This name was not validly published in Matsuoka (1987, p.56) since the generic name
Brigantedinium was not validly published at that time. Age: Holocene.
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Original description: [Matsuoka, 1987]:
Brigantedinium asymmetricum sp. nov.
Plate 5, figures 10-12 ; Text-fig. 4B
Derivation of name : Latin a+symmetricus, non+symmetry ; with reference to the asymmetrical archeopyle.
Diagnosis : Small chorate cyst brownish-pigmented, consisting of smooth autophragm, without ornament on its surface. Archeopyle intercalary, relatively large, and comprising one long, two intermediate, two short and one curved sides. Archeopyle ratio : 0.6-0.7.
Testa quae est globularis, parva vel intermedia in magnitudine et subfusca in colore consistit ex levi autophragmate sine ullo ornamento in superficie. Archeopyla quae est anterior et intercalaris et irregularis habet unum longum et flexum latus et duo intermedia et brevia latera.
Holotype : Slide no. AK2-2 (100.4/44.7). PI. 5, figs. 10-12, sample no. AK2, Recent sediment in Akkeshi Bay, Hokkaido, North Japan.
Dimensions : Cyst diameter 30.0-32.8 μm (Holotype 31.2 μm).
Number of specimens observed : 7.
Remarks : This spherical cyst resembles Brigantedinium cariacoense (Wall) in possessing a curved principal archeopyle suture, but differs from
the latter in that its archeopyle is irregularly hexagonal in shape. The specimens of Protoperidinium sp. cf. conicoides similar to the present
species are recorded from modern Carifornia Current surface sediments by Wall (1986 MS.).
Equivalent thecate form : Probably a species of the subgenus Archaeperidinium in the genus Protoperidinium based on the shape of archeopyle corresponding to the 2a plate, but its thecate species has been unknown.
Brigantedinium asymmetricum Matsuoka, 1987, p.56, pl.5, figs.10–12; text-fig.4B ex Head, 1996b, p.1231. Holotype: Matsuoka,
1987, pl.5, figs.10–11. This name was not validly published in Matsuoka (1987, p.56) since the generic name
Brigantedinium was not validly published at that time. Age: Holocene.
---------------------------------------------------------------------------------------------------
Original description: [Matsuoka, 1987]:
Brigantedinium asymmetricum sp. nov.
Plate 5, figures 10-12 ; Text-fig. 4B
Derivation of name : Latin a+symmetricus, non+symmetry ; with reference to the asymmetrical archeopyle.
Diagnosis : Small chorate cyst brownish-pigmented, consisting of smooth autophragm, without ornament on its surface. Archeopyle intercalary, relatively large, and comprising one long, two intermediate, two short and one curved sides. Archeopyle ratio : 0.6-0.7.
Testa quae est globularis, parva vel intermedia in magnitudine et subfusca in colore consistit ex levi autophragmate sine ullo ornamento in superficie. Archeopyla quae est anterior et intercalaris et irregularis habet unum longum et flexum latus et duo intermedia et brevia latera.
Holotype : Slide no. AK2-2 (100.4/44.7). PI. 5, figs. 10-12, sample no. AK2, Recent sediment in Akkeshi Bay, Hokkaido, North Japan.
Dimensions : Cyst diameter 30.0-32.8 μm (Holotype 31.2 μm).
Number of specimens observed : 7.
Remarks : This spherical cyst resembles Brigantedinium cariacoense (Wall) in possessing a curved principal archeopyle suture, but differs from
the latter in that its archeopyle is irregularly hexagonal in shape. The specimens of Protoperidinium sp. cf. conicoides similar to the present
species are recorded from modern Carifornia Current surface sediments by Wall (1986 MS.).
Equivalent thecate form : Probably a species of the subgenus Archaeperidinium in the genus Protoperidinium based on the shape of archeopyle corresponding to the 2a plate, but its thecate species has been unknown.